In a hotspot area in which an LTE system is applied, when a majority of users in the area perform communication simultaneously for various reasons, or when an activity such as a major gathering or important matches involving a large population takes place, a case in which large quantities of users access the system occurs, resulting in a quick increase of system resource usage, and a case of network over-congestion or overload occurs, and consequently, users that require emergency calls may be unable to access the system to perform communication.
Currently, to resolve a problem that an operator still can ensure that high-priority users can perform communication in a case in which congestion occurs in an LTE system, the operator allocates one or more access classes to common users in a live network. One class in class 0 to class 9 is allocated to each user. For some special users, one or more access classes in access classes 11 to 15 are further allocated. A higher class indicates that a corresponding user has a higher priority. By means of class allocation, when a case of congestion occurs in the system, the operator ensures communication and access of high-priority users by controlling access of low-priority users.
However, the foregoing mechanism is applied to access of user equipment in idle mode. When more user equipments access the network, and there is severe congestion or heavy load in the network, user equipments in connected mode still initiate new service calls or perform data transmission. Consequently, some high-priority user equipments that are really in emergencies are unable to smoothly access the network, and user experience is affected.